The present invention is related to water softening systems for dishwasher, laundry and other appliances so as to economically produce superior water quality and to require less detergent for cleaning. More particularly, the present system is related to laundry, dishwasher and other appliances incorporating thermally regenerable ion exchange materials in cartridges which are easily mounted and exchanged as needed so as to provide a built-in water softening funcion.
At present, dishwasher and laundry appliance units do not include built in water softening devices. Instead, large, central chemically activated water softening units are employed. These units soften all water which is used throughout the home or business. This can be needlessly expensive since water which does not need softening is nonetheless treated.
However, water hardness principally due to concentrations of divalent species such as calcium and magnesium cause undesirable problems. In particular, the presence of such materials, particularly at concentrations greater than about 120 parts per million cause soap to be wasted, cause spotting in dishwashers and also cause scale formation in pipes. Systems which treat these hard water problems typically do so through the addition of chemicals to regenerate conventional water softening resins and the like. This is inconvenient and expensive and additionally, unnecessarily adds salt concentrations to the wastewater.
Accordingly, it is desirable to provide deionized water, that is softened water, only to those appliances for which hard water is a particular problem. It is also seen that it is desirable to employ a water softening system which is easy to operate and maintain and which may in fact be operable through conventional automatic timed cycle fluid valve operation such as that conventionally found on dishwashers and fabric washing units. It is also seen that it is desirable to employ a water softening system in which the degree of deionization is controllable.